Xiaoxue Cheng


Image quality metrics for visual instruments were examined in terms of their through focus behavior in the presence of various aberrations, and their correlations with available subjective performance data. The contrast sensitivity measurements were performed using rotationally symmetric, variable contrast difference-of-gaussians (DOG) targets, viewed through specially designed telescopes that presented various amounts of monochromatic aberrations. Then the contrast sensitivity ratios were correlated with the image quality metrics of the telescopes. The results show that an appropriately defined integral of the instrument-observer MTF (called MTFa) correlates well with subjective performance in most cases and predicts the optimum focus best; the radius that encircles 84% of the energy of the point spread function (called Rg4) gives good correlation in some cases including the DOG experiment

Library of Congress Subject Headings

Optical instruments--Calibration; Optical instruments--Measurement

Publication Date


Document Type


Department, Program, or Center

Chester F. Carlson Center for Imaging Science (COS)


Mouroulis, Pantazis

Advisor/Committee Member

Pelz, Jeff

Advisor/Committee Member

Ninkov, Zoran


Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works. Physical copy available through RIT's The Wallace Library at: QC372 .C483 1996


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